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Message-ID: <6a223f1c-8c8b-8d07-1cf5-9a83949d0fd3@starfivetech.com>
Date:   Wed, 22 Mar 2023 18:50:38 +0800
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Subject: Re: [PATCH v3 5/5] dts: usb: add StarFive JH7110 USB dts
 configuration.
Content-Language: en-US
To:     Roger Quadros <rogerq@kernel.org>, Rob Herring <robh@kernel.org>,
        "Pawel Laszczak" <pawell@cadence.com>
CC:     Emil Renner Berthing <emil.renner.berthing@canonical.com>,
        Conor Dooley <conor@kernel.org>, Vinod Koul <vkoul@kernel.org>,
        Kishon Vijay Abraham I <kishon@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Peter Chen <peter.chen@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-phy@lists.infradead.org>, <linux-usb@vger.kernel.org>,
        <linux-riscv@lists.infradead.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>
References: <20230315104411.73614-1-minda.chen@starfivetech.com>
 <20230315104411.73614-6-minda.chen@starfivetech.com>
 <20230320153419.GB1713196-robh@kernel.org>
 <2311a888-8861-ade6-d46f-caff4fc3ec73@starfivetech.com>
 <c3d32c0c-43e0-ee62-d372-27cb09feb82e@kernel.org>
From:   Minda Chen <minda.chen@starfivetech.com>
In-Reply-To: <c3d32c0c-43e0-ee62-d372-27cb09feb82e@kernel.org>
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On 2023/3/22 16:00, Roger Quadros wrote:
> Hi Minda,
> 
> On 21/03/2023 14:35, Minda Chen wrote:
>> 
>> 
>> On 2023/3/20 23:34, Rob Herring wrote:
>>> On Wed, Mar 15, 2023 at 06:44:11PM +0800, Minda Chen wrote:
>>>> USB Glue layer and Cadence USB subnode configuration,
>>>> also includes USB and PCIe phy dts configuration.
>>>>
>>>> Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
>>>> ---
>>>>  .../jh7110-starfive-visionfive-2.dtsi         |  7 +++
>>>>  arch/riscv/boot/dts/starfive/jh7110.dtsi      | 54 +++++++++++++++++++
>>>>  2 files changed, 61 insertions(+)
>>>>
>>>> diff --git a/arch/riscv/boot/dts/starfive/jh7110-starfive-visionfive-2.dtsi b/arch/riscv/boot/dts/starfive/jh7110-starfive-visionfive-2.dtsi
>>>> index a132debb9b53..c64476aebc1a 100644
>>>> --- a/arch/riscv/boot/dts/starfive/jh7110-starfive-visionfive-2.dtsi
>>>> +++ b/arch/riscv/boot/dts/starfive/jh7110-starfive-visionfive-2.dtsi
>>>> @@ -236,3 +236,10 @@
>>>>  	pinctrl-0 = <&uart0_pins>;
>>>>  	status = "okay";
>>>>  };
>>>> +
>>>> +&usb0 {
>>>> +	status = "okay";
>>>> +	usbdrd_cdns3: usb@0 {
>>>> +		dr_mode = "peripheral";
>>>> +	};
>>>> +};
>>>> diff --git a/arch/riscv/boot/dts/starfive/jh7110.dtsi b/arch/riscv/boot/dts/starfive/jh7110.dtsi
>>>> index f70a4ed47eb4..17722fd1be62 100644
>>>> --- a/arch/riscv/boot/dts/starfive/jh7110.dtsi
>>>> +++ b/arch/riscv/boot/dts/starfive/jh7110.dtsi
>>>> @@ -362,6 +362,60 @@
>>>>  			status = "disabled";
>>>>  		};
>>>>  
>>>> +		usb0: usb@10100000 {
>>>> +			compatible = "starfive,jh7110-usb";
>>>> +			clocks = <&stgcrg JH7110_STGCLK_USB0_LPM>,
>>>> +				 <&stgcrg JH7110_STGCLK_USB0_STB>,
>>>> +				 <&stgcrg JH7110_STGCLK_USB0_APB>,
>>>> +				 <&stgcrg JH7110_STGCLK_USB0_AXI>,
>>>> +				 <&stgcrg JH7110_STGCLK_USB0_UTMI_APB>;
>>>> +			clock-names = "lpm", "stb", "apb", "axi", "utmi_apb";
>>>> +			resets = <&stgcrg JH7110_STGRST_USB0_PWRUP>,
>>>> +				 <&stgcrg JH7110_STGRST_USB0_APB>,
>>>> +				 <&stgcrg JH7110_STGRST_USB0_AXI>,
>>>> +				 <&stgcrg JH7110_STGRST_USB0_UTMI_APB>;
>>>> +			starfive,stg-syscon = <&stg_syscon 0x4 0xc4 0x148 0x1f4>;
>>>> +			starfive,sys-syscon = <&sys_syscon 0x18>;
>>>> +			status = "disabled";
>>>> +			#address-cells = <1>;
>>>> +			#size-cells = <1>;
>>>> +			ranges = <0x0 0x0 0x10100000 0x100000>;
>>>> +
>>>> +			usbdrd_cdns3: usb@0 {
>>>> +				compatible = "cdns,usb3";
>>>
>>> This pattern of USB wrapper and then a "generic" IP node is discouraged 
>>> if it is just clocks, resets, power-domains, etc. IOW, unless there's an 
>>> actual wrapper h/w block with its own registers, then don't do this 
>>> split. Merge it all into a single node.
>>>
>> I am afraid it is difficult to merge in one single node. 
>> 
>> 1.If cadence3 usb device is still the sub device. All the dts setting are in
>> StarFive node. This can not work.
>> StarFive driver code Using platform_device_add generate cadenc3 usb platform device. 
>> Even IO memory space setting can be passed to cadence3 USB, PHY setting can not be passed.
>> For the PHY driver using dts now. But in this case, Cadence3 USB no dts configure.
>> 
>> 2. Just one USB Cadence platform device.
>> Maybe this can work. But Cadence USB driver code cdns3-plat.c required to changed.
>> 
>> Hi Peter Pawel and Roger
>>    There is a "platform_suspend" function pointer in "struct cdns3_platform_data"，
>>    Add "platform_init" and "platform_exit" for our JH7110 platform. Maybe it can work.
>>    Is it OK?   
> 
> Once you move all the syscon register modifications from your wrapper driver
> to your PHY driver, only clock and reset control are left in your wrapper driver.
> This is generic enough to be done in the cdns3,usb driver itself so you don't need a
> wrapper node.
> 
> Pawel, do you agree?
>  
move all the syscon codes to PHY driver is ok. I found dwc3/dwc3-of-simple.c is public codes
and contain just clock and reset control codes. I can change the residual codes to public codes.
But I found rockchip 3399 usb dts which is one of dwc3 simple platform still contain two nodes.
See Documentation/devicetree/bindings/usb/rockchip,rk3399-dwc3.yaml
>>>> +				reg = <0x0 0x10000>,
>>>> +				      <0x10000 0x10000>,
>>>> +				      <0x20000 0x10000>;
>>>> +				reg-names = "otg", "xhci", "dev";
>>>> +				interrupts = <100>, <108>, <110>;
>>>> +				interrupt-names = "host", "peripheral", "otg";
>>>> +				phys = <&usbphy0>;
>>>> +				phy-names = "cdns3,usb2-phy";
>>>
>>> No need for *-names when there is only 1 entry. Names are local to the 
>>> device and only to distinguish entries, so 'usb2' would be sufficient 
>>> here.
>>>
>> The PHY name 'cdns3,usb2-phy'  is defined in cadence3 usb driver code.
>> Cadence USB3 driver code using this name to get PHY instance.
>> And all the PHY ops used in Cadence3 USB sub device. 
>>>> +				maximum-speed = "super-speed";
>>>> +			};
>>>> +		};
>>>> +
>>>> +		usbphy0: phy@10200000 {
>>>> +			compatible = "starfive,jh7110-usb-phy";
>>>> +			reg = <0x0 0x10200000 0x0 0x10000>;
>>>> +			clocks = <&syscrg JH7110_SYSCLK_USB_125M>,
>>>> +				 <&stgcrg JH7110_STGCLK_USB0_APP_125>;
>>>> +			clock-names = "125m", "app_125";
>>>> +			#phy-cells = <0>;
>>>> +		};
>>>> +
>>>> +		pciephy0: phy@10210000 {
>>>> +			compatible = "starfive,jh7110-pcie-phy";
>>>> +			reg = <0x0 0x10210000 0x0 0x10000>;
>>>> +			#phy-cells = <0>;
>>>> +		};
>>>> +
>>>> +		pciephy1: phy@10220000 {
>>>> +			compatible = "starfive,jh7110-pcie-phy";
>>>> +			reg = <0x0 0x10220000 0x0 0x10000>;
>>>> +			#phy-cells = <0>;
>>>> +		};
>>>> +
>>>>  		stgcrg: clock-controller@10230000 {
>>>>  			compatible = "starfive,jh7110-stgcrg";
>>>>  			reg = <0x0 0x10230000 0x0 0x10000>;
>>>> -- 
>>>> 2.17.1
>>>>
> 
> cheers,
> -roger